1. Field of the Invention
The present invention relates to a cleaning device for cleaning off carbon, dust, and other dirt deposited on the inner wall of an intake pipe passage or intake tappets of an engine of an automobile etc.
2. Description of the Related Art
In general, an engine of an automobile etc., as shown schematically in FIG. 7, is comprised of a cylinder block A1 at the bottom of which is formed a crankcase A2 in which is provided a crankshaft A3. The crankshaft A2 is linked to a piston A6 provided to be able to move freely up and down in a cylinder chamber A5.
At the top of the cylinder block A1 is attached a cylinder head A10 provided with an intake tappet A7, exhaust tappet A8B and spark plug A9.
The cylinder head A10 Is connected to one end of an intake pipe passage A11. At the other end of the intake pipe passage A11 is attached an air cleaner A12. In the middle of the intake pipe passage A11 are further arranged a throttle valve A13, venturi of a carburetor A14, choke valve A15, etc.
A float chamber A16 of the carburetor A14 is designed to be fed with gasoline from a fuel tank A17 through a fuel line A18 by a fuel pump A19.
The float chamber A16 has arranged in it a not shown float valve. The float valve automatically adjusts the amount of the gasoline fed from the fuel line A18 to the float chamber A16 so that the level of the gasoline in the float chamber A16 is maintained constant at all times.
Note that excess gasoline fed into the float chamber A16 by the fuel pump A19 is returned to the fuel tank A17 by a return line A20.
Further, the cylinder head A10 has connected to it one end of an exhaust pipe passage A21. In the middle of the exhaust pipe passage A21 is provided a catalytic converter A22 for breaking down the NOx etc. in the exhaust gas. At the other end is attached an exhaust muffler A23 for muffling the sound of the exhaust.
In an engine configured as explained above, in the process of the exhaust tappet A8 closing, the intake tappet A7 opening, and the piston A6 descending, outside air flows through the intake pipe passage A11 through the air cleaner A12 and passes through the venturi of the carburetor A14. The increase in flow rate at this time causes a negative pressure by which the gasoline in the float chamber A16 is sucked out and sprayed into the intake air passage A11 as a mist.
The resultant air-fuel mixture of the gasoline and air flows into the cylinder A5 by the further descent of the piston A6.
Next, when the piston A6 rises in a state with both of the intake tappet A7 and the exhaust tappet A8 closed, the air-fuel mixture in the cylinder chamber A5 is compressed. When the piston A6 reaches close to top dead center, the spark plug A9 is charged and the air-fuel mixture in the combustion chamber A5 is ignited.
The explosive combustion of the air-fuel mixture causes the pressure in the combustion chamber A5 to sharply rise. As a result, the piston A6 is pushed down and a rotational force is caused at the crankshaft A3 through a connecting rod A4.
Next, the piston A6 again rises. In the process, when the exhaust tappet A8 is opened, the combustion gas in the combustion chamber A5 is exhausted from the exhaust pipe passage A21 to the outside of the engine.
If the engine is used for a long time in this way, carbon, dust, etc. deposit and accumulate inside the intake pipe passage A11 and at the intake tappet A7 and become a cause impairing the smooth operation of the throttle valve A13 or intake tappet A7 etc. and reducing the intake efficiency.
Therefore, in the past, as shown in FIG. 8, the fuel line A18 has been directly connected to the return line A20 connecting to the fuel tank A17 without connecting the fuel line A18 to the float chamber A16 and a feed line A25 and return line A26 of a separately prepared cleaning device 24 have been connected to the float chamber A16 for cleaning operation of the intake pipe passage A11.
The cleaning device A24 is provided with a tank A2 in which a mixture of a washer and gasoline is stored, a pump A28 for pumping the mixture in the tank A27 into the float chamber A16, a throttle valve A29 for adjusting the flow rate of the mixture, a manometer A30 for displaying the pressure of the mixture in the feed line A25, etc. and supplies the mixture in the tank into the float chamber A16 by the pump A28.
When the engine is run with the cleaning device A24 attached to the float chamber A16, the float chamber A16 is supplied with the mixture of the washer and gasoline instead of gasoline and the mixture sprayed as a mist from the venturi of the carburetor A14 to the intake pipe passage A11.
While the mist or gasified mixture passes through the inside of the intake pipe passage A11 or intake tappet A7, the washer contained in the mixture removes the carbon, dust, and other dirt deposited on the inside wall of the intake pipe passage A11 or intake tappet A7 and flushes it into the cylinder chamber A5.
There, the gas of the mixture and the carbon, dust, etc. entrained in it are burned by the ignition of the spark plug The combustion gas is exhausted from the exhaust tappet through the exhaust pipe passage to the outside as exhaust gas.
As another method of cleaning an intake system of an automobile engine, for example, as disclosed in Japanese Unexamined Patent Publication (Kokai) No. 10-61456, there is known the method of cleaning an intake system by using a special nozzle to inject and spray a washer inside the throttle chamber of an automobile engine equipped with an electronically controlled fuel injection system.
In a first aspect of the method of cleaning disclosed in Japanese Unexamined Patent Publication (Kokai) No. 10-61456, a blowby hose connected to the connection line of the air duct is detached and instead a special nozzle is set through a plug comprised of silicone rubber etc. connected to a tube leading to a washer container. The washer is injected and sprayed into the throttle chamber from an injection port of the nozzle.
In a second aspect of the method of cleaning disclosed in Japanese Unexamined Patent Publication (Kokai) No. 10-61456, the top lid of an air cleaner of an engine provided with a throttle chamber with a built-in air flow meter directly below the air cleaner is detached and a special nozzle used to inject and spray a washer inside the throttle chamber from a position past the air flow meter through a mesh at the top of the air flow meter.
In both the method of the first and second aspects explained above, the washer is injected and sprayed into the throttle chamber while running the engine. The engine is continued to run idle after spraying until there is no longer any smoke, that is, the washer remaining in the engine has been all burned, and the cleaning operation then ended.
Summarizing the problems to be solved by the present invention, in the cleaning device A24 of the related art shown in FIG. 8, since the work of cleaning the intake pipe passage A11 included the step of detaching the gas line A18 and return line A20 connecting the float chamber A16 of the carburetor A14 and the fuel tank A17 and connecting the fuel line A25 and return line A26 of the cleaning device A24 to the float chamber A16, special facilities for the cleaning work and specialized skills were required. General users therefore could not do the cleaning work by themselves.
On the other hand, with the cleaning methods disclosed in Japanese Unexamined Patent Publication (Kokai) No. 10-61456, an aerosol can was used for the washer container. With diesel engines or the recent high compression ratio gasoline engines, however, there was the danger of the propane propellant filled inside the aerosol can for spraying the washer spontaneously igniting and exploding when the temperature inside the cylinder chamber rose in the process of the compression stroke of the piston and the excessive pressure caused at that time causing the connecting rod etc. to bend.
An object of the present invention is to provide a cleaning device which solves the above problems of the related art and enables the easy, safe cleaning of the intake pipe passage of various types of engines Without requiring special facilities or skills.
According to the present invention, there is provided a cleaning device of an intake pipe passage of an engine comprising a container storing a washer; an air feed line with one end connected to a source of compressed air and with another end communicated with the inside of the container for feeding compressed air from the compressed air source to the inside of the container; a washer feed line with one end communicated with the inside of the container for supplying from the bottom of the container the washer compressed by the compressed air; a spray nozzle connected to the other end of the washer feed line; and a pilot valve interposed in the middle of the washer feed line and opened and closed cyclically by a cyclic pilot pressure generated by an air pulse circuit operating by air of an air source.
Preferably, further provision is made of a container holder having a holding face provided with a seal member for sealing the area around the bottom end of the container filled with the washer, a clamp member for bringing the area around the bottom end face in close contact with the seal member and clamping the container to the holding face, and a cutter provided to be able to be projected and retracted from the holding face at the inner circumference of the seal member for breaking through the bottom end of the container clamped on the holding face at the projecting position to form an opening; the air feed line and washer feed line are connected to the container holder, compressed air of the air feed line Is introduced from the opening of the container formed by the cutter into the container, and that compressed air is used to send the washer in the container through the opening from the washer feed line toward the spray nozzle.
More preferably, the spray nozzle is comprised of a nozzle body for spraying the washer and a nozzle holder provided with a plurality of readily elastically deformable support legs flared outward radially in one direction from the axial direction of the nozzle body, and the nozzle holder can be attached to or detached from the nozzle body selectively from the direction where the front ends of the support legs flare to the front outward past the front end of the nozzle body and the direction where they flare outward to the rear of the nozzle body.